<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>10 padding</title>
  <style>
    .box {
      width: 200px;
      height: 200px;
      background-color: palevioletred;
      /*padding-left: 1000px;*/
    }

    .damao {
      background-color: #7FFFD4;
      height: 200px;
      padding-left: 20px;
      /*继承的宽度不会撑开*/
    }
  </style>
</head>
<body>
<div class="box">
  <div class="damao">123</div>
</div>
</body>
</html>